Simplify the following expression: $k = \dfrac{5}{4p} + \dfrac{10}{7p}$
Explanation: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4p$ and $7p$ $\lcm(4p, 7p) = 28p$ $ k = \dfrac{7}{7} \cdot \dfrac{5}{4p} + \dfrac{4}{4} \cdot \dfrac{10}{7p} $ $k = \dfrac{35}{28p} + \dfrac{40}{28p}$ $k = \dfrac{35 +40}{28p}$ $k = \dfrac{75}{28p}$